Answer :
Bx + Cy = D
Solve for y . . .
*subtract Bx from both sides
Bx - Bx + Cy = D - Bx
Cy = D - Bx
*now divide both sides by C
Cy/C = (D - Bx)/C
Cy/C = D/C - Bx/C
y = D/C - (B/C)x
y = -(B/C)x + D/C
Solve for y . . .
*subtract Bx from both sides
Bx - Bx + Cy = D - Bx
Cy = D - Bx
*now divide both sides by C
Cy/C = (D - Bx)/C
Cy/C = D/C - Bx/C
y = D/C - (B/C)x
y = -(B/C)x + D/C